This invention relates to a communications line control system and more specifically relates to a control system for controlling and recording the use of long-distance communication circuits.
In the past the control and recordation of long-distance telephone calls was performed by a PABX or CENTREX operator who selected the outgoing long-distance lines over which a call was to be placed either by selecting bulk rate lines, such as WATS lines, foreign exchange lines or tie lines, or in the alternative, if these lines were not available, selected a local trunk line. This method of controlling and recording telephone calls has proved to be costly and inefficient and accordingly, attempts have been made to control the placing of telephone calls and the recordation thereof on a more efficiently controlled basis. Thus, for example, with respect to the recordation of telephone calls, a number of systems have been developed for recording the use of long-distance telephone communication circuits. Baichtal, et al. disclosed in U.S. Pat. No. 3,825,689 an automatic message metering and storage system. Each of a plurality of subscriber lines is scanned in sequence with each subscriber line having an associated unique location in a memory unit. This system records information resulting from long-distance, toll and other type of telephone services. However, it does not provide any means for selectively connecting long-distance lines so as to minimize the cost of the telephone call. Along somewhat the same technological lines as the Baichtal et al development, LeStrat et al. developed, as disclosed in U.S. Pat. No. 3,651,269, a telephone accounting system wherein each of a plurality of toll junctures associated with each of a plurality of trunk lines is scanned by command of a computer. Predetermined storage areas in the computer are allotted to each trunk line wherein data regarding the time of transfer of the long-distance call is stored in the memory location associated with the line being scanned, with this information being utilized later to generate a bill to the calling party. The system is located in a toll exchange so that centralized charging of each of the subscribers using the long-distance lines can be achieved.
Caithmaer, et al. provided a central telephone message accounting system as disclosed in U.S. Pat. No. 3,829,617 which has a central processing unit for receiving data with respect to the identity of a calling party, the nature of the call and the duration of the call. Thus, a juncture is positioned on each of a plurality of trunk lines with the junctures being scanned for telephone calls being placed. When a telephone call is detected, the call is connected via a branch line to a data receiver. The data is stored and then re-sent to a remote toll office where the call is completed. Other systems have been developed for recording the use of long-distance trunk lines on an automatic basis to thereby provide information to a central processing unit for preparing telephone bills as disclosed in Joel U.S. Pat. No. 3,760,110 and Woolf, et al. U.S. Pat. No. 3,806,652. However, none of these systems discloses a switching system wherein telephone calls are switched at remote satellite locations such that the cost of any particular call is minimized.
Telephone metering systems have been combined with private automatic branch exchanges to provide a combined switching and metering function. Thus, Gayler, et al. disclosed in U.S. Pat. No. 3,870,823 a metering system for use with a PABX in connection with direct distance dialed, WATS and extended area service telephone communications lines. The system includes both a PABX and a central processing unit with switching matrices and detecting circuits for addressing each of a plurality of long-distance trunk lines with sample addresses synchronous with the addressing of receivers within the metering system so that the receiver can sample and analyze the information on the trunk line. As in the case of the aforementioned traffic metering developments, this system does not provide a method or apparatus for switching long-distance communications lines in order to minimize the cost of long-distance telephone calls.
Of even greater importance to telephone subscribers is the fact that the hardware for controlling the connection of long-distance telephone lines in accordance with any criteria, such as line availability, is expensive. To control the connection of long-distance lines in accordance with the criterion that the least expensive available line will be connected first, wherein the least expensive line may vary with many parameters such as, the line type, restricted use and position in a rotary, results in even additional expenses. Accordingly, in the past it has not been commercially feasible to provide at each PABX or CENTREX unit, a switching system having computerized control so as to connect long-distance lines in order to minimize the cost of long-distance telephone calls except through the provision of dedicated costly computerized switching equipment. Steps have been taken in the art, as exemplified by Gebhardt, et al. U.S. Pat. No. 3,225,144, Vigliante, et al. U.S. Pat. No. 3,268,669 and Joel U.S. Pat. No. 3,731,000 for controlling the interconnection of telephone lines between a local office and a toll office by means of a remotely positioned central processing unit. The advantage of such a system is that only one computer is required to control a plurality of remote switching circuits. Thus, the cost of the computer per switching circuit is substantially reduced. None of the systems disclosed in the aforementioned patents, however, teaches or suggests an arrangement wherein an efficient and inexpensive means is provided for controlling and monitoring the connection of long-distance telephone circuits for the purpose of minimizing the cost of the long-distance telephone calls connected through the switching systems between the customer's location(s) and one or more local or central toll offices.
It accordingly is an object of this invention to provide an improved system for controlling and monitoring the connection of long-distance telecommunications lines for the purpose of minimizing the cost of long-distance telephone communications.
It is another object of this invention to provide an improved method and apparatus for remotely controlling the connection of long distance telecommunications lines on the basis of a least cost routing.